What Atrophic Gastritis Means
Atrophic gastritis is the loss of normal gastric glands, replaced by connective tissue or abnormal epithelium (metaplasia), occurring on a background of chronic inflammation primarily caused by Helicobacter pylori infection or autoimmunity. 1
Core Definition and Pathophysiology
Atrophic gastritis represents a preneoplastic condition and a critical step in the multistep cascade toward gastric adenocarcinoma. 1 The condition involves:
- Loss of appropriate gastric glandular structures replaced by either:
- Connective tissue (nonmetaplastic atrophy), or
- Different, non-native epithelium such as intestinal metaplasia (metaplastic atrophy)
- Chronic inflammation as the underlying background process
- Progressive transformation through the Correa cascade: chronic gastritis → atrophic gastritis → intestinal metaplasia → dysplasia → gastric adenocarcinoma 1
Two Main Etiologies
H. pylori-Associated Atrophic Gastritis (Most Common)
- Accounts for the dominant etiology globally 1
- Creates multifocal atrophy with patchy distribution
- Rate ratio of 5.0 for developing atrophic gastritis compared to uninfected individuals 1
- Additional risk factors include age, tobacco use, and high-salt diet 1
Autoimmune Gastritis (Less Common)
- Prevalence approximately 0.5-2% of the population 1
- Causes corpus-restricted oxyntic gland destruction
- Results in severe hypochlorhydria and hypergastrinemia
- More common in women and those with other autoimmune diseases 1
Critical Clinical Recognition Point
The presence of intestinal metaplasia on gastric biopsy almost invariably implies underlying atrophic gastritis, even when atrophy is not explicitly documented on the pathology report. 1 This is because intestinal metaplasia develops within atrophic mucosa, though pathologists often fail to note the atrophy distinctly.
Why It Matters: Cancer Risk
Atrophic gastritis is not a benign finding—it represents an important preneoplastic stage with:
- Markedly increased gastric cancer risk, particularly with extensive anatomic involvement 1
- Progression through a well-defined precancerous cascade
- Different neoplastic risks depending on etiology:
- H. pylori-associated: intestinal-type gastric adenocarcinoma
- Autoimmune: type 1 gastric neuroendocrine tumors (NETs) plus adenocarcinoma 1
Diagnosis Requirement
Regardless of etiology, the diagnosis must be confirmed by histopathology—clinical or endoscopic features alone are insufficient. 1 Endoscopic features (pale mucosa, visible vasculature, loss of folds) should prompt biopsy, but histologic confirmation is mandatory for definitive diagnosis and risk stratification.